[reprint] Mass extinction and the rise of the dinosaurs

Growing quickly helped the earliest dinosaurs and other ancient reptiles flourish in the aftermath of mass extinction

Eoraptor lunensis lived roughly 230 million years ago, at a time when dinosaurs were small and rare.
Jordan Harris courtesy of Kristi Curry Rogers, CC BY-SA

Kristi Curry Rogers, Macalester College

It may be hard to imagine, but once upon a time, dinosaurs didn’t dominate their world. When they first originated, they were just small, two-legged carnivores overshadowed by a diverse array of other reptiles.

How did they come to rule?

My colleagues and I recently studied the fossilized bones of the earliest known dinosaurs and their nondinosaur rivals to compare their growth rates. We wanted to find out whether early dinosaurs were somehow special in the way they grew – and if this may have given them a leg up in their rapidly changing world.

Before dinosaurs – the Great Dying

Life on Earth was flourishing 250 million years ago. Dinosaurs had yet to evolve. Instead, giant amphibians and sail-backed reptiles called therapsids thrived.

But within a blink of geologic time, in a span of about 60,000 years, scientists estimate 95% of all living things went extinct. Known as the Permian extinction or the Great Dying, it is the largest of the five known mass extinction events on Earth.

Most scientists agree this near total die-off was caused by extensive volcanic activity in modern-day Siberia, which covered millions of square miles with lava. The resulting noxious gases and heat combined to push global temperatures dramatically upward, eventually leading to ocean acidification, a loss of oxygen in ocean waters and a profound ecosystem collapse, both on land and in the ocean.

Only a few lucky survivors made it through.

The survivors and their descendants

In the ecological vacuum after the mass extinction event, on the stage of a healing Earth, the ancestors of dinosaurs first evolved – along with the ancestors of today’s frogs, salamanders, lizards, turtles and mammals. It was the dawn of the Triassic Period, which lasted from 252 million years ago to 201 million years ago.

Collectively, the creatures that survived the Great Dying were not particularly remarkable. One animal group, known as Archosauria, started off with relatively small and simple body plans. They were flexible eaters and could live in a wide variety of environmental conditions.

Archosaurs eventually split into two tribes – one group including modern crocodiles and their ancient relatives and a second including modern birds, along with their dinosaur ancestors.

This second group walked on their tiptoes and had big leg muscles. They also had extra connections between their back bones and hip bones that allowed them to move efficiently in their new world.

Instead of directly competing with other archosaurs, it seems this group of dinosaur ancestors exploited different ecological niches – maybe by eating different foods or living in slightly different geographical areas. But early on, the dinosaurlike archosaurs were far less diverse than the crocodile ancestors they lived alongside.

Slowly, the dinosaur lineage continued to evolve. It took tens of millions of years before dinosaurs became abundant enough for their skeletons to show up in the fossil record.

Aerial shot of a barren, weathered and rocky landscape.
The Ischigualasto Provincial Park in San Juan Province, Argentina, where the earliest dinosaur fossils have been discovered.
Kristi Curry Rogers, CC BY-SA

The oldest known dinosaur fossils come from an area in Argentina now called Ischigualasto Provincial Park. Rocks there date back to roughly 230 million years ago.

The Ischigualasto dinosaurs include all three dinosaur groups: the meat-eating theropods, the ancestors of giant sauropods and the plant-eating ornithischians. They include Herrerasaurus, Sanjuansaurus, Eodromaeus, Eoraptor, Chromogisaurus, Panphagia and Pisanosaurus.

These early dinosaurs represent only a small fraction of animals found from that time period. In this ancient world, the crocodilelike archosaurs were on top. They had a wider array of body shapes, sizes and lifestyles, easily outpacing early dinosaurs in the diversity race.

It wouldn’t be until closer to the end of the Triassic Period, when another volcanism-induced mass extinction event occurred, that dinosaurs got their lucky break.

The late Triassic extinction event killed 75% of life on Earth. It decimated the crocodilelike archosaurs but left early dinosaurs relatively untouched, paving the way for their rise to dominance.

Before long, dinosaurs went from representing less than 5% of animals on Earth to constituting more than 90%.

Bones tell the story of growth

My collaborators from the Universidad Nacional de San Juan, Argentina, and I wondered whether the rise of dinosaurs may have been underpinned, in part, by how fast they grew. We know, through microscopic study of fossilized bones, that later dinosaurs had fast growth rates – much faster than that of modern-day reptiles. But we didn’t know whether that was true for the earliest dinosaurs.

We decided to examine the microscopic patterns preserved in thigh bones from five of the earliest known dinosaur species and compare them with those of six nondinosaur reptiles and one early relative of mammals. All the fossils we studied came from the 2-million-year interval within the Ischigualasto Formation of Argentina.

Microscopic image of a crosssection of bone tissue with many details present.
Eoraptor bone tissue under a polarizing light microscope shows evidence of rapid, continuous growth – common to both the earliest dinosaurs and many of their nondinosaur contemporaries.
Kristi Curry Rogers, CC BY-ND

Bones are an archive of growth history because, even in fossils, we can see the spaces where blood vessels and cells perforated the mineralized tissue. When we look at these features under a microscope, we can see how they are organized. The more slowly growth occurs, the more organized microscopic features will be. With quicker growth, the more disorganized the microscopic features of the bone look.

We discovered early dinosaurs grew continuously, not stopping until they reached full size. And they did indeed have elevated growth rates, on par with and, at times, even faster than those of their descendants. But so did many of their nondinosaur contemporaries. It appears most animals living in the Ischigualasto ecosystem grew quickly, at rates that are more like those of living mammals and birds than those of living reptiles.

Our data allowed us to see the subtle differences between closely related animals and those occupying similar ecological niches. But most of all, our data shows that fast growth is a great survival strategy in the aftermath of mass destruction.

Scientist still don’t know exactly what made it possible for dinosaurs and their ancient ancestors to survive two of the most extensive extinctions Earth has ever undergone. We are still studying this important interval, looking at details such as legs and bodies built for efficient, upright locomotion, potential changes in the way the earliest dinosaurs may have breathed and the way they grew. We think it’s probably all these factors, combined with luck, that finally allowed dinosaurs to rise and rule.The Conversation

Kristi Curry Rogers, Professor of Biology and Geology, Macalester College

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Continue reading “[reprint] Mass extinction and the rise of the dinosaurs”

The Return of the Brontosaurus

Remember the brontosaurus vs apatosaurus debate? Turns out both sides were right…we think…so far.

Here’s the skinny: The skeleton of a long-necked, long-tailed dinosaur was unearthed in Wyoming by paleontologist Othniel Charles Marsh in 1879, according to the Natural History Museum in London. At the time, scientists dubbed the giant plant eater, which lived during the Jurassic period about 150 million years ago, Brontosaurus excelsus, according to Yale University.

However, in 1903, paleontologist Elmer Riggs found that B. excelsus was very similar to another dinosaur, Apatosaurus ajax, which Marsh discovered in Colorado in 1877, the Natural History Museum noted. The differences between the dinosaurs appeared so minor that scientists decided it was better to place them both in the same genus, or group of species. Because Apatosaurus was named first, the rules of scientific naming kept its name, leading scientists to retire the name Brontosaurus.

More than 100 years later, researchers suggested reviving Brontosaurus as its own genus. A 2015 study of sauropods in the journal PeerJ found that the original Apatosaurus and Brontosaurus fossils may have been different enough to classify them as separate groups.

The nearly 300-page study examined 477 physical features of 81 sauropod specimens. The initial aim of the research was to analyze the relationships between the species making up the family of sauropods known as Diplodocidae, which includes Diplodocus, Apatosaurus and, now, Brontosaurus.

All in all, the scientists found that Brontosaurus’ neck was higher-set, narrower and smaller than Apatosaurus’, study lead author Emanuel Tschopp, a vertebrate paleontologist now at the University of Hamburg in Germany, told Live Science. They suggested three known species of Brontosaurus: B. excelsus, B. parvus and B. yahnahpin.

“They call Brontosaurus ‘resurrected,'” Jacques Gauthier, curator of reptiles at the Yale Peabody Museum of Natural History, who did not participate in this study. “I like the ring of that. ‘Restored’ is a perfectly correct term, but ‘resurrected’ is the official description of what they have done.”

Tschopp noted that they could not have made this discovery 15 or more years before their study; only recently did findings of dinosaurs similar to Apatosaurus and Brontosaurus help reveal what made these groups unique.

It has been nearly a decade since the paper published, and Tschopp noted that “not everybody accepts such proposals immediately. There have been — and still are — researchers who don’t trust the results quite yet and continue to use the name Apatosaurus for what I call Brontosaurus.”

Mike Taylor, a vertebrate paleontologist at the University of Bristol in England who did not take part in the 2015 study, told Live Science in an email, “you rarely get consensus from paleontologists on these matters, so the answer you get will depend on who you ask. There’s been no pushback in the formal literature, but I’ve heard a bit of grumbling.”

Still, to Taylor, the call to “resurrect” Brontosaurus “just feels like a reasonable thing to do.” He noted that the 2015 study “made a solid argument that most specialists found pretty persuasive and not especially surprising.” Taylor and his colleagues have mentioned B. excelsus and B. parvus in their own studies a number of times.

Better Living Through Sauerkraut

I wish I had been taught Chemistry differently. To this day, most of the chemistry I learned in school was as a side-benefit of my biology classes. I loved bio, and survived chemistry (required) and physics (ditto) in order to take the advanced biology class my senior year, wherein a good deal of chemistry was taught in passing, particularly when we were looking at DNA and genetics. But beyond that, Chemistry the subject seemed utterly detached from things I cared about. Okay, some times you just have to buckle down and get through the classes you don’t much care about (I’m looking at you, PE) to get your ticket punched and make your way out of high school. But I think I would have learned more if it had been related to something else. Like food.

Flash forward a few decades to when I gave a lesson in bread-making to my daughter’s second grade class. It’s a perfect basic chemistry lesson for kids: simple enough to be reduced to 7-year-old level, but tied to something familiar (better yet, edible). I just came across the handout I did for the class, which is what put me in mind of it.

And this morning, spurred by an article in NY Times Cooking, I made sauerkraut. It is ridiculously easy: cut up a head of cabbage, put resulting shreds in a bowl, “massage” (the NYT term, not mine) two tablespoons of Kosher salt into the shreds for five minutes, until the cabbage starts to soften, reduce down, and release some liquid. Then pack into jars and stir every couple of hours, to speed fermentation. All the time I was up to my elbows in cabbage I kept wondering 1) is this really going to work? and 2) why does it work. So as soon as I had packed the cabbage into its jars and cleaned up the mayhem that cutting up cabbage produces, I hied me to the internet.

According to the Clemson University website, “Cabbage is converted to sauerkraut due to growth and acid production by a succession of lactic acid bacteria. Salt and limited air creates desirable conditions for the leuconostocs – a group of less acid tolerant lactic acid bacteria that grow better at 60°F to 70°F.” Fortunately for my sauerkraut, the winter temperature of my kitchen is somewhere around 65°. The salt works–as I noted as I worked–to soften and draw juice from the cabbage. As a bonus, it also works to keep undesirable bacteria at bay; you want the desirable bacteria, of course: the leuconostoc lactic acid bacteria that create lactic acid. 

See? Chemistry!

The Clemson site gives a recipe that requires 25 pounds of cabbage and yields 9 quarts. I suspect that once my much more modest batch has fermented fully, it will be something closer to a quart and a half.

All of this reminds me that I need to make a batch of bread and butter pickles. For science!

The Green Skies of Mars and Other Astronomical Wonders

Astronauts on Mars may see a green sky, eerie new study suggests


Using the European Space Agency‘s (ESA) ExoMars Trace Gas Orbiter (TGO), scientists have observed Mars‘ atmosphere glowing green for the first time ever — in the visible light spectrum, that is. The effect is called airglow (or dayglow or nightglow, depending on the hour). Nightglow “occurs when two oxygen atoms combine to form an oxygen molecule,” according to ESA. On Mars, this happens at an altitude of approximately 31 miles (50 km). Scientists have suspected Mars to have airglow for some 40 years, but the first observation only occurred a decade ago by ESA’s Mars Express orbiter, which detected the phenomenon in the infrared spectrum. Then, in 2020, scientists observed the phenomenon in visible light using TGO, but in Martian daylight rather than at night. Now, we’ve seen the phenomenon at night via TGO.

Moon is 40 million years older than we thought, tiny crystals from Apollo mission confirm

The moon is at least 40 million years older than we once thought, a new study reveals. Scientists confirmed our cosmic companion’s new minimum age after reanalyzing tiny impact crystals from lunar samples taken by NASA’s Apollo 17 mission in 1972. Earth is approximately 4.54 billion years old. So based on the newest study, the zircon crystals were formed around 80 million years after our planet formed. However, the collision that birthed the moon could have actually happened even earlier. After the Earth-Thea crash, the infant moon’s surface would have been covered by a magma ocean due to the intense energy of the collision. Therefore, the lunar zircon crystals could only have properly solidified into their current state once the magma ocean had cooled down.

The oldest continents in the Milky Way may be 5 billion years older than Earth’s

Astrobiologists think a planet needs to have certain features to support life: oxygen in its atmosphere, something to shield organisms from dangerous radiation and liquid water, for a start. Although big land masses aren’t strictly necessary for living things to emerge, Earth’s history shows that they’re important for life to thrive and exist for long periods of time. So, if an exoplanet had continents before Earth, it follows that there might be older, more advanced life on that world.

This line of thought led Jane Greaves, an astronomer at Cardiff University astronomer in the U.K., to answer the question: When did the first continents appear on a planet in our galaxy? Turns out, two exoplanets’ continents — and perhaps life — may have arisen four to five billion years before Earth’s.

Can a Dead Star Keep Exploding?
If the Tasmanian Devil is a type of dead star, it’s not behaving like the others. As a dead star, the light coming from it could signal its transition into a sort of stellar afterlife. It could be a new type of stellar corpse.
“Because the corpse is not just sitting there, it’s active and doing things that we can detect,” Ho said. “We think these flares could be coming from one of these newly formed corpses, which gives us a way to study their properties when they’ve just been formed.”
The Echoes From Inflation Could Still Be Shaking the Cosmos Today
In the very early universe, physics was weird. A process known as “inflation,” where best we understand the universe went from a single infinitesimal point to everything we see today, was one such instance of that weird physics. Now, scientists from the Chinese Academy of Science have sifted through 15 years of pulsar timing data in order to put some constraints on what that physics looks like.
Life Might Be Easiest to Find on Planets that Match an Earlier Earth

When methane (CH4) and oxygen (O2) are both present in an atmosphere, it’s an indication that life is at work. That’s because, in an oxygen environment, methane only lasts about 10 years. Its presence indicates disequilibrium. For it to be present, it has to be continually replenished in amounts that only life can produce.

Continue reading “The Green Skies of Mars and Other Astronomical Wonders”

New Evidence on How the Dinosaurs Died

Such a cool article from Universe Today, I think it merits a post all to itself!

Devastating Clouds of Dust Helped End the Reign of the Dinosaurs

When a giant meteor crashed into Earth 66 million years ago, the impact pulverized cubic kilometers of rock and blasted the dust and debris into the Earth’s atmosphere. It was previously believed that sulfur from the impact and soot from the global fires that followed drove a global “impact winter” that killed off 75% of species on Earth, including the dinosaurs.

A new geology paper says that the die-off was additionally fueled by ultrafine dust created by the impact which filled the atmosphere and blocked sunlight for as long as 15 years. Plants were unable to photosynthesize and global temperatures were lowered by 15 degrees C (59 F).

Most scientists agree the disaster started with an asteroid impact, where an asteroid at least 10 kilometers wide struck the Chicxulub region in the present-day Yucatán Peninsula in Mexico. The impact released 2 million times more energy than the most powerful nuclear bomb ever detonated.

The devastation created layer of ash sandwiched between layers of rock, known as the Cretaceous-Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K-T) boundary, which is found across the world in the geologic record. It includes a layer of iridium, an element common in asteroids but rare on Earth. It was this ‘iridium anomaly’ that first revealed the extinction event as an asteroid strike to geologists more than three decades ago.

What has been debated is what created conditions for the post-impact winter. The leading candidates were sulphur from the asteroid’s impact, or soot from global wildfires that ensued after the impact. Both would have blocked out sunlight and plunged the world into a long, dark winter, collapsing the food chain and creating a chain reaction of extinctions.  

Overview of the Cretaceous-Paleogene boundary in North Dakota (USA). The sediments indicate a river and swamp-like environment at the end of the age of the dinosaurs. The pink-brown layer yields ejecta debris derived from the Chicxulub impact event and the grain-size data from this interval were used as input parameters for the paleoclimate modeling study (photo: Pim Kaskes).

But in this new research, scientists from the Royal Observatory of Belgium (ROB) studied new sediment samples taken from the Tanis fossil site in North Dakota in the US, which captures a 20-year period during the aftermath of the asteroid impact. Analysis of the samples revealed evidence of silicate dust particles, particles that were ejected into the atmosphere and eventually settled back down on the planet.

“We specifically sampled the uppermost millimeter-thin interval of the Cretaceous-Paleogene boundary layer,” said Pim Kaskes  from the Archaeology, Environmental Changes & Geo-chemistry (AMGC) at the Vrije Universiteit Brussel (VUB) and the Vrije Universiteit Amsterdam (VUA), who was also involved in the study. “This interval revealed a very fine and uniform grain-size distribution, which we interpret to represent the final atmospheric fall-out of ultrafine dust related to the Chicxulub impact event. The new results show much finer grain-size values than previously used in climate models and this aspect had important consequences for our climate reconstructions.”

Based on their findings, the scientists also created a new paleoclimate computer model that evaluated the roles of sulfur, soot, and silicate dust on the post-impact climate.

Conceptual model of the Chicxulub impact plume showing different stages of (a) production, and (b) transport and deposition of the impact-generated ejecta (not to scale). (c) Paleoclimate model simulations showcasing the time evolution of the dust-induced photosynthetic active radiation flux across the planet following the Chicxulub impact 66 million years ago (modified from Senel et al., 2023; Nature Geoscience).

“The new paleoclimate simulations show that such a plume of micrometric silicate dust could have remained in the atmosphere for up to 15 years after the event, contributing to global cooling of the Earth’s surface by as much as 15 °C in the initial aftermath of the impact,” said Cem Berk Senel from ROB, the lead author of the study.

But while the dust was a contributor to the catastrophic conditions, the sulfur and soot were also a factor.

“We suggest that, together with additional cooling contributions from soot and sulfur, this is consistent with the catastrophic collapse of primary productivity in the aftermath of the Chicxulub impact,” the researchers wrote.

The prolonged disruption in photosynthesis would pose severe challenges for both terrestrial and marine habitats and mass extinctions would occur in groups not adapted to survive the dark, cold, and food-deprived conditions for at least two years. The researchers said this matches the paleontological records, which show that any plants or animals that could enter a dormant phase (for example, through seeds, cysts, or hibernation in burrows) and were able to adapt to an omnivorous diet, or weren’t dependent on one particular food source generally better survived the K-Pg event.

Continue reading “New Evidence on How the Dinosaurs Died”

The Joys of Infrastructure

cover for How Infrastructure WorksI just finished a wonderful book that explained what it would take for everyone on Earth to live the good life. It was all about infrastructure.

Don’t stop reading! Infrastructure is far from boring, I promise you, especially when the person explaining it to you is Deb Chachra, an engineering professor who both understands how things work and how to explain them. (I’ll just note right here that she has read some science fiction and philosophy along the way.)

The book is called How Infrastructure Works: Inside the Systems that Shape Our World. And no, it’s not a treatise on pipes or wiring or highway construction. It’s an overview of how all those things come together to make modern life possible.

Even if you’ve thought a lot about infrastructure — most of us only think about it when ours fails — this book will give you some deep insights into just how important it is and, even more importantly, how infrastructure design sets in place all our lives.

One of the first things I got from the book is that modern infrastructure is what makes our lives comfortable and possible in the United States and other highly developed countries. We have power at the flick of a switch, water when we turn on a tap, phone service (land lines even still exist, though most of us are using mobile phones these days). The wastewater gets taken away and treated.

Further, we have roads that go everywhere. In some places, we also have other transit options besides cars.

Most of us have access to good food even if we don’t live near where food is grown. That’s due to shipping systems, which also bring us other things we need.

That’s the point: all these things make modern life possible. We don’t have to dig our own wells or fetch water from the nearest creek (if there is one). We don’t have to cut up logs and feed them into a wood burning stove to cook and keep our homes warm. We can be in touch with people all around the world without leaving home or even waiting for the mail (and of course, mail is an infrastructure).

A couple of hundred years ago, people didn’t have most of these things. There were roads and there were shops and some supply systems, but they were not nearly as convenient as they are today.

Despite the fantasy of the “freedom” of living off the grid, the truth is that living in a system with modern infrastructure gives people a great deal more freedom to do something beyond just survival. Continue reading “The Joys of Infrastructure”

Miracle and Wonder

So my kid had a vertebra removed. (CW: surgery)

Let me back up. I am a long-time medical history nerd; I wrote a whole book that touched on medieval medical education and midwifery, and (as one does) I left 90% of my research on the cutting room floor. My favorite factoid–which did make it into the book–is that around 1200 or so the European medical establishment came up with a new way to treat a broken leg: a splint to help the bone heal in its proper alignment. Because up to that point the treatment was to bend the leg so that the heel touched the buttock and tie it in that position, essentially self-splinting. Of course, once the bone healed, the leg was, if not useless, badly malformed. Splinting seems like a simple fix–but of course, it was controversial at the time.

So was hand-washing, when it comes to that. When Ignaz Semmelweis discovered that the incidence of maternal death in puerperal fever post-childbirth could be reduced from almost 20% to 2% by the simple expedient of antiseptic procedure–hand-washing using chlorinated line solution, he was attacked by the medical establishment. As near as I can tell, they were insulted by the notion that they might be infecting their patients–even if they were coming directly from treating a septic wound to delivering a baby. Semmelweis couldn’t explain the mechanism of infection–it wasn’t until after his death that Louis Pasteur confirmed the germ theory and Joseph Lister popularized antiseptic procedure. Poor Ignaz had a breakdown (or was said to have had one by the colleagues who had him institutionalized) and he died of gangrene from a wound he got at the asylum.

That was 166 years ago. There was no question about hand-washing or germ theory at the hospital where the kid was treated. And there was a whole lot of stuff that seemed miraculous to my eyes. Over the course of just-a-titch over 11 hours, the neurosurgeon went in, took out the offending vertebra, put in a bone graft taken from a rib, wrapped the whole thing in a “cage” around which new bone will grow, and fused the new graft to two vertebrae on either side. The fact that they can do this at all takes my breath away (as the kid’s husband put it, “to us, it’s a miracle, but to the doctor it’s Thursday”). There are the small patient-comfort things that they do which can have an outsized effect on patient outcome–the drapes or garments that fill with warmed air to keep the patient warm during the surgery, for one, and all the monitoring to make sure that nothing in the rest of the body is slipping sideways while the surgeon was doing his work. I cannot even number all the things the anesthesiologist was tracking.

And then there’s this: nerve conduction monitoring. When you’re putting screws into vertebrae, you don’t want to get too close to the myriad nerves that run through the spinal column. Bad Things Could Happen. So they wired the kid to monitor nerve conduction in all her limbs, but especially in the legs and feet. And the monitoring was done by attendants in Idaho. Which doesn’t inspire awe until you learn that the surgery was taking place in California. Rather than fill up the operating room with extra bodies keeping track of nerve conduction, it’s easier and less costly and more effective to do it virtually. And by Jove, she came through with all the nerves and sensation intact.

As near as I can tell from a quick Google, vertebral corpectomy (removing a vertebra) has been around since the 1950s. I suspect that it was not, at the time, the routine high-success-rate procedure it is now. For nearly 70 years they’ve been refining the process and the tools, getting it closer to right, just in time for my daughter to need it. There’s a lot about medicine as it is practiced in this country that needs work. But all this week I’ve had this running through my head:

These are the days of miracle and wonder…
Medicine is magical and magical is artThink of the boy in the bubbleAnd the baby with the baboon heart

–Paul Simon, The Boy in the Bubble

[reprint] Psychedelics, Transformation, and the Brain

I admit to being a biology nerd. Nothing delights me more than understanding how our brains work. This reprint offers a fascinating glimpse into how psychedelics might turbo-charge change (insight? enlightenment? feelings of transcendent peace?).

Psychedelics plus psychotherapy can trigger rapid changes in the brain − new research at the level of neurons is untangling how

New research hints at how psychedelics can trigger rapid, lasting change.
wildpixel/iStock via Getty Images Plus

Edmund S. Higgins, Medical University of South Carolina

The human brain can change – but usually only slowly and with great effort, such as when learning a new sport or foreign language, or recovering from a stroke. Learning new skills correlates with changes in the brain, as evidenced by neuroscience research with animals and functional brain scans in people. Presumably, if you master Calculus 1, something is now different in your brain. Furthermore, motor neurons in the brain expand and contract depending on how often they are exercised – a neuronal reflection of “use it or lose it.”

People may wish their brains could change faster – not just when learning new skills, but also when overcoming problems like anxiety, depression and addictions.

Clinicians and scientists know there are times the brain can make rapid, enduring changes. Most often, these occur in the context of traumatic experiences, leaving an indelible imprint on the brain.

But positive experiences, which alter one’s life for the better, can occur equally as fast. Think of a spiritual awakening, a near-death experience or a feeling of awe in nature.

a road splits in the woods, sun shines through green leafy trees
A transformative experience can be like a fork in the road, changing the path you are on.
Westend61 via Getty Images

Social scientists call events like these psychologically transformative experiences or pivotal mental states. For the rest of us, they’re forks in the road. Presumably, these positive experiences quickly change some “wiring” in the brain.

How do these rapid, positive transformations happen? It seems the brain has a way to facilitate accelerated change. And here’s where it gets really interesting: Psychedelic-assisted psychotherapy appears to tap into this natural neural mechanism.

Psychedelic-assisted psychotherapy

Those who’ve had a psychedelic experience usually describe it as a mental journey that’s impossible to put into words. However, it can be conceptualized as an altered state of consciousness with distortions of perception, modified sense of self and rapidly changing emotions. Presumably there is a relaxation of the higher brain control, which allows deeper brain thoughts and feelings to emerge into conscious awareness.

Psychedelic-assisted psychotherapy combines the psychology of talk therapy with the power of a psychedelic experience. Researchers have described cases in which subjects report profound, personally transformative experiences after one six-hour session with the psychedelic substance psilocybin, taken in conjunction with psychotherapy. For example, patients distressed about advancing cancer have quickly experienced relief and an unexpected acceptance of the approaching end. How does this happen?

glowing green tendrils of a neuron against a black background
Neuronal spines are the little bumps along the spreading branches of a neuron.
Patrick Pla via Wikimedia Commons, CC BY-SA

Research suggests that new skills, memories and attitudes are encoded in the brain by new connections between neurons – sort of like branches of trees growing toward each other. Neuroscientists even call the pattern of growth arborization.

Researchers using a technique called two-photon microscopy can observe this process in living cells by following the formation and regression of spines on the neurons. The spines are one half of the synapses that allow for communication between one neuron and another.

Scientists have thought that enduring spine formation could be established only with focused, repetitive mental energy. However, a lab at Yale recently documented rapid spine formation in the frontal cortex of mice after one dose of psilocybin. Researchers found that mice given the mushroom-derived drug had about a 10% increase in spine formation. These changes had occurred when examined one day after treatment and endured for over a month.

diagram of little bumps along a neuron, enlarged at different scales
Tiny spines along a neuron’s branches are a crucial part of how one neuron receives a message from another.
Edmund S. Higgins
A mechanism for psychedelic-induced change

Continue reading “[reprint] Psychedelics, Transformation, and the Brain”

Sometimes Vindication Happens

I am thrilled to see Dr. Katalin Karikó and her research partner Dr. Drew Weissman win the Nobel Prize in medicine for their work on messenger RNA (mRNA).

It’s not just that their years of work provided the basis for the mRNA vaccines against Covid that have saved so many lives and protected even more people from serious illness. More important to me is that Dr. Karikó stuck to her research despite being shoved aside — she’s an adjunct professor — and never getting grants.

She believed in the potential for mRNA and she was right even though no one paid any attention to her except Dr. Weissman. “No one” includes prestigious journals like Nature and Science.

There are a lot of implications in all this.

First, I find Dr. Karikó an excellent role model for scientists, inventors, writers, artists, activists, and the many others who have a vision of something that can be done. Hang in there. You might succeed in what you’re doing and even might be recognized for it.

But let’s admit that being recognized is a long shot, especially in one’s lifetime. All too many of our great artists and even scientists died broke, with their work only being acknowledged much later.

I suspect it is even more common that people do good work that never gets noticed, maybe never even gets used. It’s not them, it’s the system, and we are all the poorer for those losses.

And of course, some people hang onto a vision that is, in fact, lunacy. In truth, though, I think far more people who have a vision worth pursuing give up because it’s too damn hard.

I tend to hope that everyone who sees something important, something vital, something perhaps only they see stays with it despite a lack of support. This is core to our humanity. Continue reading “Sometimes Vindication Happens”

Living in the Anthropocene

According to First Dog on the Moon (I do rigorous research for these essays), some geologists have decided that the Earth moved from the Holocene into the Anthropocene in 1950.

Although First Dog also points out that there is a bit of scientific kerfuffle over that date, I’ve decided to go with it. By the time anyone dealing with what constitutes an epoch makes it official, I will probably have shuffled off this mortal coil, so I have to make to do with the facts I have.

The thing I like best about choosing 1950 as a date is that it means my entire life (give or take a year) has been lived in the Anthropocene. And that feels about right to me.

Given the current disaster news – the Gulf of Mexico off the Florida coast is about the temperature of a nice hot tub right now and that’s not even the worst thing going on – the years of my lifetime feel like the end result of the work of that segment of humanity who believe the purpose of life is their personal dominion over the planet, all of its other life forms, and most people.

While there is a dangerous sect of religious dominionists, the secular kind have done most of the damage. The human race over my lifetime appears to have been well-populated with people who can look at a beautiful landscape and think of all the ways to destroy it so that they can make something imaginary, which is to say money.

A lifetime that includes “plastics” (why, yes, I did see The Graduate back in the day), vast expansion of nuclear bombs and nuclear power without equal understanding of what we were doing, and human-engineered existential threat (I’m not talking about chatbots) seems like a perfect place to start the anthropocene.

I mean, I grew up a mile from an oil refinery. Continue reading “Living in the Anthropocene”